15 July 2009

Can Your Brain Fight Fatigue?

Recently, researchers in England discovered that simply rinsing your mouth with a sports drink may fight fatigue. In the experiment which was published online in February in the Journal of Physiology,
eight well-trained cyclists completed a strenuous, all-out time trial
on stationary bicycles in a lab. The riders were hooked up to machines
that measured their heart rate and power output. Throughout the ride,
the cyclists swished various liquids in their mouths but did not
swallow. Some of the drinks contained carbohydrates, the primary fuel
used during exercise. The other drinks were just flavored, sugar-free
water.

By the end of the time trials, the cyclists who had rinsed with the
carbohydrate drinks — and spit them out — finished significantly faster
than the water group. Their heart rates and power output were also
higher. But when rating the difficulty of the ride, on a numerical
scale, their feelings about the effort involved matched those for the
water group.

In a separate portion of the experiment, the scientists, using a
functional M.R.I., found that areas within the brain that are
associated with reward, motivation and emotion were activated when
subjects swished a carbohydrate drink. It seems that the brains of the
riders getting the carbohydrate-containing drinks sensed that the
riders were about to get more fuel (in the form of calories), which
appears to have allowed their muscles to work harder even though they
never swallowed the liquid.